Early introduction of food reduces food allergy – Does it?

Excerpt

Food allergy is a common disease and appears to increase in many countries. Some people call it even the second wave of the allergy epidemic. Whereas some countries such as Australia have very high rates of food allergy, it appears to be no problem in other parts of the world 1. Even within the small area of Europe, there seem to be dramatic differences in prevalence rates with high occurrence of food allergy in the northern parts, especially the United Kingdom, but lower frequencies in southern parts, especially Greece 2. The reason for this is still not well understood.Prevention of food allergy has been tried since many decades and the question whether early introduction of allergenic food reduces food allergy or not is currently highly debated. In this current issue, you will find a statement in favor of early feeding from our Australian colleague Debra Palmer, who performed intervention studies for hen's egg allergy and a statement raising concern from Michael Perkin, our colleague from the United Kingdom, who performed the trial on introduction of six allergenic foods in breast‐fed infants.Debra Palmer argues that high‐quality randomized controlled trial evidence has given us the confidence to swallow the concept that allergenic foods, like egg and peanut, should be given to infants early on (Palmer in current issue). In contrast, Michael Perkin raises the concerns that the implementation in the real world would not work and that the long‐term impact on nutritional consequences is unknown (Perkins in current issue). Moreover, he has safety concerns.Both authors are from countries with high prevalence rates of food allergy where changes of the guidelines might improve their situation. However, we always should have the whole picture in mind. UK and Australia are not the whole world, and there are many countries with low incidence of food allergies. Especially in these countries, changes might result in the opposite than what we aim for.There seems in general an agreement on the concept that food sensitization occurs via the skin in children with a disturbed skin barrier function in an environment with high food allergen exposure and that this might be prevented due to induction of early tolerance through early oral feeding 4. Therefore, we have two conditions that will influence the outcome in a child at risk for the development of food allergy: first the exposure from the environment that might cause sensitization and second the oral exposure that might cause tolerance. We have to carefully look at the conditions in every country. Moreover, this might be even different for various allergens.In the UK, peanuts seem to be consumed frequently. Peanut consumption results in an increase in peanut allergens in house and bed dust 5. This might cause sensitization in infants at risk. These infants could be protected through early oral feeding 6. Feeding every child peanut products early on will increase peanut consumption and peanut allergens in the environment. This could result in an even higher risk of sensitization, but we can prevent this through oral feeding. However, everybody has to know this and has to be compliant. Michael Perkin pointes nicely out that in the LEAP trial, the study team did not allow participating families the option of non‐compliance. Every LEAP family was called more than 100 times to remind them to eat or avoid peanut (Perkins in current issue).What about other countries? In Greece, peanuts seem not be a common food. Peanut allergens in the environment should be low and children with eczema will not get sensitized without allergen exposure.